Surgical stapling instruments used for applying parallel rows of staples through compressed living tissue are well known in the art, and are commonly used for closure of tissue or organs prior to transection, prior to resection, or in anastomoses, and for occlusion of organs in thoracic and abdominal plasty procedures. One known pneumo-intestinal surgical stapling instrument of this type has been in use for many years, and is currently available under the trade designation "The PI Stapler", catalog #3960 by Minnesota Mining and Manufacturing Company (3M), St. Paul, Minn., the use of which stapler is described in a publication entitled "Surgical Stapling, Gastric and Small Bowel Procedures, Volume I" ISBN 0-937433-00-4, Library of Congress Catalog Number 85-082599 available from Minnesota Mining and Manufacturing Company (3M), St. Paul, Minn., the contents of which are herein incorporated by reference. That stapler and a similar stapler described in Freund et al. PCT Application No. WO 83/02247, published Jul. 7, 1983 are adapted for firing staples into compressed living tissue from a staple filled cartridge. The staplers have anvil and jaw portions, a cartridge holder including a removable cartridge and a handle lever.
Typically, a "PI" type stapler is positioned adjacent the tissue to be stapled, the anvil and jaw portions are approximated adjacent the tissue to be stapled, and the stapler is clamped on the tissue by moving the handle lever in a first movement to cause the cartridge holder to move toward the anvil placing the cartridge into a staple firing position. Moving the handle lever in a second movement "fires" the stapler (e.g. it ejects the staples from the cartridge).
In some surgical procedures the clamping force results in tissue that is highly compressed to ensure, inter alia, proper hemostasis in the tissues being stapled. The clamping force is present in various degrees in each of the surgical procedures for a "PI" type surgical stapler. Such a clamping force causes tissue trauma in the tissue to be stapled, at least to some degree.
The prior art "PI" type staplers encounter problems because it is difficult to determine when they are loaded with a "spent" cartridge or with a cartridge that does not contain staples. On occasion, a spent cartridge may be inadvertently left in a stapler after it has been fired during a surgical procedure where the stapler is used several times for the same patient, or a spent cartridge may be inadvertently loaded into a stapler that is about to be fired in the patient. If a stapler is loaded with a cartridge housing other than a ready-to-fire cartridge housing and the stapler is clamped on tissue to be stapled, the compressive forces created by the stapler subject the tissue to undesirable and unnecessary trauma. The sequence of (1) clamping the stapler with a spent cartridge on tissue, (2) firing the "dud" stapler (3) subsequently rearming, (4) again approximating the stapler adjacent the tissue to be stapled and (5) reclamping the stapler wastes precious time during the surgical procedure.
Additionally, the prior art "PI" type staplers may be used in procedures in which the surgeon uses a scalpel to manually create an incision on a side of closed staples (e.g. the procedure described in the article entitled "Resection of the Lesion" on pages 14 and 15 of the publication entitled "Surgical Stapling, Gastric and Small Bowel Procedures, Volume I", ISBN 0-937433-00-4, Library of Congress Catalog Number 85-082599 available from Minnesota Mining and Manufacturing Company (3M), St. Paul, Minn.). A spent stapler cartridge used in such procedures may result in unnecessary blood loss, inadequate hemostasis and tissue trauma for the patient undergoing the procedure.
Surgical stapler cartridge safety devices are described in U.S. Pat. Nos. 4,863,088 and 4,955,959, and U.S. patent application Ser. No. 07/629,597. The firing mechanisms in those staplers sequentially close staples into tissue. Since each staple is closed within tissue one after another in succession, the force required to fire such staplers is generally less than the force required to fire a "PI" type stapler where all the staples are generally closed in tissue at the same time.
Unlike the present invention wherein the same part (e.g. a lever or "handle") is operable in both a first movement to approximate and clamp tissue and a second movement to close all the staples within tissue generally simultaneously, the "ILA" type staplers described in U.S. Pat. Nos. 4,863,088 and 4,955,959, and U.S. patent application Ser. No. 07/629,597 utilize separate and distinct member to (1) sequentially fire the staples (e.g. a firing tab or button) and (2) clamp onto the tissue (an element of the stapler that does not include the firing tab or button).